The present invention relates to methods for a file server (e.g. NAS (Network Attached Storage)) for arranging data in storage devices and controlling power management of storage media in the storage devices.
In recent years, there are an increasing number of services supplying stream content (e.g. video) to user terminals via the Internet (hereinafter referred to as “streaming services”) and a wide variety of content is handled by such services. In an on-line movie delivery service, for example, delivering a great number of movies to the users (irrespective of whether each movie is popular or not) has become important in order to precisely meet the preferences of each user. Further, with the increase in services letting users freely register videos shot by themselves and share such registered videos, the diversity and capacity of content are increasing with accelerating speed.
Meanwhile, with the increasing ground swell toward global environmental protection, more and more efforts are being made also in the information technology industry to reduce electric power consumption of devices. For storage devices, the technology called “MAID” (Massive Array of Inactive Disks), which makes it possible to individually start/stop each hard disk of a device having a large number of hard disks, is attracting great attention.
In the streaming service, an item of stream content is read out from a storage device and supplied on demand to the user requesting the content. Also for such streaming services, methods for reducing the power consumption of a storage device by employing MAID are being examined.
For example, a technique for reducing the power consumption of a storage device without deteriorating its quick response to content playback requests has been disclosed in JP-A-2003-85871. In the technique, an item of content is split into multiple parts and stored in separate hard disks. The hard disks storing the parts of the content are successively started up in sync with the playback of the content.